Semiconductor devices containing integrated circuits (ICs) are used in a wide variety of electronic apparatus. The IC devices (or chips) comprise a miniaturized electronic circuit that has been manufactured on the surface of a substrate (or die) of semiconductor material. The circuits are composed of many overlapping layers, including layers containing dopants that can be diffused into the substrate (called diffusion layers) or ions that are implanted (implant layers) into the substrate. Other layers are conductors (polysilicon or metal layers) or connections between the conducting layers (via or contact layers). IC devices can be fabricated in a layer-by-layer process that uses a combination of many steps, including imaging, deposition, etching, doping, and cleaning. One of the latter steps in the semiconductor fabrication process forms the packaging that is used to protect the IC device from environmental hazards.
After it has been formed, the semiconductor package is often used in an ever growing variety of electronic applications, such as point of load buck converters, DrMos in disk drives, USB controllers, portable computer devices, cellular phones, digital music players, and so forth. Depending on the size of the die and the electronic application, the semiconductor package may be highly miniaturized and may need to be as small as possible.